8060A
Instruction Manual
5-26
Table 5-7. Troubleshooting Guide (cont)
Test and Symptom Possible Cause/Suggestions
Voltage Test - DC (cont)
High impedance dc readings
0.00 normal dc
readings correct
R1
DC readings incorrect for
all ranges
Leakage from pcb, U3-6/7,
contamination
DC readings correct for
200 mV, 2V-incorrect
for 20V, 200V, 1000V
Input divider or input divider switches,
R2
Voltage Test - AC
DC reading correct,
ac readings incorrect
Switches S3D, S3B
Check power supply connections
J13 Vss
J7 Com
J12 Vdd
Resistance/Conductance Test
All ranges incorrect Ohms source voltage inadequate -
using a voltmeter in the 2V or 20V
range, measure ohms source voltage
between TP11 and common. Refer to
Table 5-8 for correct values.
Q3, Q4, RT1, R2, R1, Z5
CR1 not supplying enough current
(particularly if 200Ω range noisy).
Select diode test, connect an external
1 kΩ resistor across the inputs and
measure the voltage drop across the
resistor - should be approximately 1V
(±10%).
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